1. Field of the Invention
The present invention relates to a sheath liquid for a particle analyzer being used to analyze particles contained in a sample, a method for producing thereof, a method for analyzing particles using thereof.
2. Description of the Related Art
A particle analyzer based on flow cytometry is generally used to analyze particles in biological samples such as urine and blood. When a flow cytometer is used, the samples are enveloped in the stream of the sheath liquid and passed through a flow cell of the flow cytometer. Electrical or optical information from the samples when passing is detected by a detecting section in the flow cell, thereby analyzing particles contained in the samples.
An example of a known sheath liquid used for flow cytometer is described in U.S. Pat. No. 6,750,060. A large amount of sodium chloride is contained in this sheath liquid in order to adjust the refractive index of the sheath liquid. Use of the sheath liquid allows for accurate analysis of particles, even if a sample such as urine having a high refractive index is used as a specimen.
However, in the case where a device with the sheath liquid described in U.S. Pat. No. 6,750,060 is not used for a certain period, the precipitates may be accumulated in the interior of the device due to evaporation of the sheath liquid. Therefore, it is necessary to dismantle the device to remove the precipitates when accumulated. Additionally, materials which are highly anticorrosive to the sheath liquid may be used to make the metal portion of a device which comes in contact with the sheath liquid and regular part replacement may be needed, resulting in high production costs.